[gnome-continuous] Update Meson version

[Emmanuele Bassi <ebassi src gnome org>]

commit 05114e84b57b62f1a5d4d30999ccea24c2e1d9ec
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Mar 13 20:27:47 2019 +0000

    Update Meson version

 manifest.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/manifest.json b/manifest.json
index d2aea0a..3231404 100644
--- a/manifest.json
+++ b/manifest.json
@@ -67,7 +67,7 @@
 
                 {"src": "git:https://github.com/mesonbuild/meson.git";,
                  "name": "meson",
-                 "tag": "0.49.1",
+                 "tag": "0.50.0",
                  "component": "devel",
                  "patches": ["python-meson-buildsys.patch"]},